Stress significantly influences all aspects of health status and behavioral adaptation of diabetics. There are concomitant neuroendocrine effects as well as long-term outcomes reflecting level of adaptation to having a life-threatening chronic disease and engaging in the highly structured, stressful life style necessitated by the diabetes treatment regimen. This project compares metabolically-labile, insulin-dependent adolescent diabetics with non-labile diabetics and with non-diabetic, non-obese individuals under three specific conditions of stress --interpersonal stress, emotional but non-interpersonal stress, and physical stress (exercise). It is hypothesized that there are significant individual differences in diabetic patients' patterns of biomedical response to stress which will systematically relate to whether the patients are labile or non-labile. Behavioral variables being studied include: coping patterns; locus of control; knowledge and skill regarding diabetes; denial, anxiety, and depression; self-esteem; family dynamics; and psychosocial functioning of patient and family.